In Berlin expect a row (4)
I believe the answer is:
line
'row' is the definition.
(as in a row of things)
'in berlin expect a' is the wordplay.
'in' indicates the answer is hidden within the clue.
'LINE' is hidden in the letters of 'berlin expect a'.
(Other definitions for line that I've seen before include "job" , "classified information" , "A length without breadth or thickness" , "Row - occupation" , "Wrinkle; row" .)